/*

  * Copyright (C) The Apache Software Foundation. All rights reserved.

  *

  * This software is published under the terms of the Apache Software License

  * version 1.1, a copy of which has been included with this distribution in

  * the LICENSE file.

  * 

  * $Id: Producer.java 155459 2005-02-26 13:24:44Z dirkv $

  */

 package org.apache.commons.messenger.tool;

 import java.io.BufferedReader;

 import java.io.FileReader;

 import java.io.IOException;

 import java.io.InputStreamReader;

 import java.io.Reader;

 import javax.jms.Destination;

 import javax.jms.JMSException;

 import javax.jms.Message;

 import javax.jms.TextMessage;

 import org.apache.commons.messenger.Messenger;

 import org.apache.commons.messenger.MessengerManager;

 /** <p><code>Producer</code> is a sample program that 

   * creates messages and sends them to a given destination which

   * could either be a queue or a topc.</p>

   *

   * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>

   * @version $Revision: 155459 $

   */

 public class Producer {

     protected Messenger messenger;

     public static void main(String[] args) {

         try {

             Producer client = new Producer();

             client.run( args );

         }

         catch (JMSException e) {

             System.out.println( "Caught: " + e );

             Exception linked = e.getLinkedException();

             if ( linked != null ) {

                 System.out.println( "Underlying exception: " + linked );

                 linked.printStackTrace();

             }

             else {

                 e.printStackTrace();

             }

         }

         catch (Exception e) {

             System.out.println( "Caught: " + e );

             e.printStackTrace();

         }

     }

     public void run(String[] args) throws Exception {

         if ( args.length < 2 ) {

             System.out.println( "Usage: Producer messengerName destination [fileName]" );

             System.out.println( "If no fileName is provided then the current input stream is used" );

             return;

         }

         String name = args[0];

         String subject = args[1];

         messenger = MessengerManager.get( name );

         if ( messenger == null ) {

             throw new JMSException( "No such messenger called: " + name );

         }

         Destination destination = messenger.getDestination( subject );

         if ( destination == null ) {

             throw new JMSException( "Could not find destination: " + subject );

         }

         Reader reader = ( args.length > 2 ) 

             ? new FileReader( args[2] )

             : new InputStreamReader( System.in );

         Message message = createMessage( reader );

         messenger.send( destination, message );

         // close the JMS connection to release any background threads        

         messenger.close();

     }

     /** Creates a message from the given text file */

     protected Message createMessage(Reader in) throws Exception {

         String text = readText(in);

         TextMessage message = messenger.createTextMessage( text );

         return message;

     }

     /** Reads the given text stream into a single string */

     protected String readText(Reader in) throws IOException {

         // read all the text into memory

         StringBuffer buffer = new StringBuffer();

         BufferedReader reader = new BufferedReader( in );

         for ( String line; (line = reader.readLine()) != null; ) {

             buffer.append( line );

             buffer.append( '\n' );

         }

         reader.close();

         return buffer.toString();

     }

 }